Modified Nanoparticles With Cell Transport Peptide R8and Sec For Oral Delivery Of Proteins And Peptides

In order to improve translocation efficiency of the drug-loaded nanoparticles inthe intestinal epithelium and enhance the bioavailability of orally administeredproteins and peptides, three cell transport peptides—R8, Sec (unconventionalSecretion) and Sec-R8, have been explored for modification of nanoparticle. Celltransport peptides were synthesized using Fmoc solid phase method. In addition, threecell transport peptides were separated and depurated using Sephadex chromatographyand RP-HPLC. The tree cell transport peptides after isolation and purification wereidentified by MS that the synthesized peptide have the same mass weight with thetheoretical one. FITC-dextran, a water-solubility drug, was selected as a model, andPLGA as the carrier material, then FITC-dextran PLGA nanoparticles were preparedby a double emulsion method. The optimized formulation of nanoparticles containingFITC-dextran was conveniently obtained by the single-factor investigation and theorthogonal methodology. And then nanoparticles were modified with three kinds ofcell transport peptides respectively. Segment of jejunum of each rats was deployed forintestinal mucosa transport experiment. In this present experiment, containingFITC-dextran, nanoparticles containing FITC-dextran and cell transportpeptide-modified nanoparticles were added (Two modification methods: the firstmethod is, first of all, preparation of nanoparticles, followed by, connection of treecell transport peptides. The Second method is the synthesis of PLGA-CPP couplingcompounds, and then preparation of nanoparticles). Fluorescence spectrophotometrywas used to monitor the transport concentration of drug, then the apparentpermeability coefficient (the Papp) was calculated. The transport delivery of drug wascompared between the free drug, nanoparticles containing FITC-dextran and celltransport peptide-modified nanoparticles.The yield of the three products with the purity of95%above was obtained,which meeted experimental requirements. Under the optimal manufacture conditions(drug concentration with1mg/ml, PLGA concentration with4%, PVA concentrationwith1%, ultrasonic power with150W), FITC-dextran was entrapped68.5%, the mean diameter of the obtained nanoparticles was203nm(n=3), Zeta was-9.513mV(n=3). The nanoparticles containing drug had the features such as regular sphericalsurface and uniformly dispersion. The conclusion could be conclude through ratintestinal permeability experiments in six hours: compared with free drug, theapparent permeability coefficient (Papp) of nanoparticles containing drug in theintestinal mucosa transport increased from3.3×10-6cm/s to20.0×10-6cm/s, it suggeststhat nanoparticles containing drug improv the drug penetration capability. Comparedwith the nanoparticles containing drug, the maximum value of drug permeationamount of transport peptide-modified nanoparticles in the intestinal mucosa transportincreased from68.37ng to175.83ng,the maximum apparent permeability coefficient(Papp) increased from20.0×10-6cm/s to51.4×10-6cm/s, it suggests that transportpeptide-modified nanoparticles improve the drug penetration capability obviously,which showed that cell transport peptide-modified nanoparticle in the intestinalmucosa transport was a good system..